Primary-Secondary (Ps) Mode; Connecting Units Together In Primary/Secondary Mode - nvent SPECTRACOOL N36 Instruction Manual

PRIMARY-SECONDARY (PS) MODE

Note: during normal operation, in both the primary-secondary (PS) and lead-lag (LL) operating modes,
line 2 displays the device ID, not the outlet temperature. The outlet temperature can be viewed on line
1 by pressing arrow.
Primary-secondary (PS) mode shares the same hardware and source code as standalone mode, but offers more
functionality and features. The controller ships from the factory in Standalone Mode. PS mode is configured
manually in the field after the installation. This option allows the user to operate the air conditioner in a group
network with up to 10 units. To support PS mode, three parameters, H01, H02, and H03 need to be configured.
H01 specifies the operating mode, H02 specifies the device ID, and H03 specifies the total number of the units in
the group network.
Before configuring to operate in PS mode, the user should understand the functionality of the PS mode.
1. In the PS mode, all units operate off the cooling/heating setpoint and differential of the primary
unit. The system prevents setpoint changes from secondary units.
2. The primary unit monitors the enclosure temperatures of all the units and manages the ON/OFF
status of cooling and heating based on the unit reporting the highest temperature.
3. When cooling is initiated the primary unit energizes first. Secondary units are energized
sequentially at 10 second intervals. When heating is initiated all units turn on heat together. When
cooling or heating is satisfied all units turn off together.
4. If the number of units communicating on the network doesn't match the value in H03 then
the primary unit will display alarm LC, and the secondary units will display alarm LC1 until the
communication re-established.
5. Any unit that loses communication with the primary unit will enter standalone mode and continue
operating based on its own temperature probe until communication is re-established.
6. All temperature setpoints and alarms can be viewed remotely if one of the ACUs is equipped with
Hoffman network card (RAC module).
7. Best recommendation is to configure the ACU that has Hoffman network card to be the primary
one.

CONNECTING UNITS TOGETHER IN PRIMARY/SECONDARY MODE

Primary - Device ID 1
89215758
Secondary - Device ID 2
Primary-secondary network connectivity
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Secondary - Device ID 3
Figure 3
Secondary - Device ID 10
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